When I brought the small plant of water hyacinth from the lake we visited with my class on a nature trip, I did not realize how fast growing it was. Within a fortnight, the plant had filled my little pond and subdued the water lilies already there. After a month , it was trying to come out of the pond and attack the flowers surrounding the pond!
The flowers of the water hyacinth are a beautiful lavender. Many of the lakes in Bangalore are filled by it. It is a big nuisance because it covers the whole water body in a short time , choking other water plants and fish.
People of Bangladesh have found an intelligent way to tackle this pest. They use it to make paper, or they compost it .